This is found during review of https://reviews.llvm.org/D67088.
CHECK-DAG is non-overlapping after https://reviews.llvm.org/D47106.
-allow-deprecated-dag-overlap was introduced to temporary accept old
behavior.
But it actually hide some broken tests, eg: test/CodeGen/PowerPC/swaps-le-1.ll
The codegen has changed, but the CHECK-DAG still PASS due to allowing overlap.
This patch remove the deprecated options, and fix the broken tests.